Volume 1 – Symposium

We are pleased to present the conference proceedings for the 12th edition of the International Fluid Power Conference (IFK). The IFK is one of the world’s most significant scientific conferences on fluid power control technology and systems. It offers a common platform for the presentation and discussion of trends and innovations to manufacturers, users and scientists. The Chair of Fluid-Mechatronic Systems at the TU Dresden is organizing and hosting the IFK for the sixth time. Supporting hosts are the Fluid Power Association of the German Engineering Federation (VDMA), Dresdner Verein zur Förderung der Fluidtechnik e. V. (DVF) and GWT-TUD GmbH. The organization and the conference location alternates every two years between the Chair of Fluid-Mechatronic Systems in Dresden and the Institute for Fluid Power Drives and Systems in Aachen. The symposium on the first day is dedicated to presentations focused on methodology and fundamental research. The two following conference days offer a wide variety of application and technology orientated papers about the latest state of the art in fluid power. It is this combination that makes the IFK a unique and excellent forum for the exchange of academic research and industrial application experience. A simultaneously ongoing exhibition offers the possibility to get product information and to have individual talks with manufacturers. The theme of the 12th IFK is “Fluid Power – Future Technology”, covering topics that enable the development of 5G-ready, cost-efficient and demand-driven structures, as well as individual decentralized drives. Another topic is the real-time data exchange that allows the application of numerous predictive maintenance strategies, which will significantly increase the availability of fluid power systems and their elements and ensure their improved lifetime performance. We create an atmosphere for casual exchange by offering a vast frame and cultural program. This includes a get-together, a conference banquet, laboratory festivities and some physical activities such as jogging in Dresden’s old town.:Group A: Materials Group B: System design & integration Group C: Novel system solutions Group D: Additive manufacturing Group E: Components Group F: Intelligent control Group G: Fluids Group H | K: Pumps Group I | L: Mobile applications Group J: Fundamental

Proceedings of SIRM 2023 - The 15th European Conference on Rotordynamics

It was our great honor and pleasure to host the SIRM Conference after 2003 and 2011 for the third time in Darmstadt. Rotordynamics covers a huge variety of different applications and challenges which are all in the scope of this conference. The conference was opened with a keynote lecture given by Rainer Nordmann, one of the three founders of SIRM “Schwingungen in rotierenden Maschinen”. In total 53 papers passed our strict review process and were presented. This impressively shows that rotordynamics is relevant as ever. These contributions cover a very wide spectrum of session topics: fluid bearings and seals; air foil bearings; magnetic bearings; rotor blade interaction; rotor fluid interactions; unbalance and balancing; vibrations in turbomachines; vibration control; instability; electrical machines; monitoring, identification and diagnosis; advanced numerical tools and nonlinearities as well as general rotordynamics. The international character of the conference has been significantly enhanced by the Scientific Board since the 14th SIRM resulting on one hand in an expanded Scientific Committee which meanwhile consists of 31 members from 13 different European countries and on the other hand in the new name “European Conference on Rotordynamics”. This new international profile has also been emphasized by participants of the 15th SIRM coming from 17 different countries out of three continents. We experienced a vital discussion and dialogue between industry and academia at the conference where roughly one third of the papers were presented by industry and two thirds by academia being an excellent basis to follow a bidirectional transfer what we call xchange at Technical University of Darmstadt. At this point we also want to give our special thanks to the eleven industry sponsors for their great support of the conference. On behalf of the Darmstadt Local Committee I welcome you to read the papers of the 15th SIRM giving you further insight into the topics and presentations

Advanced Techniques for Design and Manufacturing in Marine Engineering

Modern engineering design processes are driven by the extensive use of numerical simulations; naval architecture and ocean engineering are no exception. Computational power has been improved over the last few decades; therefore, the integration of different tools such as CAD, FEM, CFD, and CAM has enabled complex modeling and manufacturing problems to be solved in a more feasible way. Classical naval design methodology can take advantage of this integration, giving rise to more robust designs in terms of shape, structural and hydrodynamic performances, and the manufacturing process.This Special Issue invites researchers and engineers from both academia and the industry to publish the latest progress in design and manufacturing techniques in marine engineering and to debate the current issues and future perspectives in this research area. Suitable topics for this issue include, but are not limited to, the following:CAD-based approaches for designing the hull and appendages of sailing and engine-powered boats and comparisons with traditional techniques;Finite element method applications to predict the structural performance of the whole boat or of a portion of it, with particular attention to the modeling of the material used;Embedded measurement systems for structural health monitoring;Determination of hydrodynamic efficiency using experimental, numerical, or semi-empiric methods for displacement and planning hulls;Topology optimization techniques to overcome traditional scantling criteria based on international standards;Applications of additive manufacturing to derive innovative shapes for internal reinforcements or sandwich hull structures

Design and Applications of Coordinate Measuring Machines

Coordinate measuring machines (CMMs) have been conventionally used in industry for 3-dimensional and form-error measurements of macro parts for many years. Ever since the first CMM, developed by Ferranti Co. in the late 1950s, they have been regarded as versatile measuring equipment, yet many CMMs on the market still have inherent systematic errors due to the violation of the Abbe Principle in its design. Current CMMs are only suitable for part tolerance above 10 μm. With the rapid advent of ultraprecision technology, multi-axis machining, and micro/nanotechnology over the past twenty years, new types of ultraprecision and micro/nao-CMMs are urgently needed in all aspects of society. This Special Issue accepted papers revealing novel designs and applications of CMMs, including structures, probes, miniaturization, measuring paths, accuracy enhancement, error compensation, etc. Detailed design principles in sciences, and technological applications in high-tech industries, were required for submission. Topics covered, but were not limited to, the following areas: 1. New types of CMMs, such as Abbe-free, multi-axis, cylindrical, parallel, etc. 2. New types of probes, such as touch-trigger, scanning, hybrid, non-contact, microscopic, etc. 3. New types of Micro/nano-CMMs. 4. New types of measuring path strategy, such as collision avoidance, free-form surface, aspheric surface, etc. 5. New types of error compensation strategy

FDSOI Design using Automated Standard-Cell-Grained Body Biasing

With the introduction of FDSOI processes at competitive technology nodes, body biasing on an unprecedented scale was made possible. Body biasing influences one of the central transistor characteristics, the threshold voltage. By being able to heighten or lower threshold voltage by more than 100mV, the very physics of transistor switching can be manipulated at run time. Furthermore, as body biasing does not lead to different signal levels, it can be applied much more fine-grained than, e.g., DVFS. With the state of the art mainly focused on combinations of body biasing with DVFS, it has thus ignored granularities unfeasible for DVFS. This thesis fills this gap by proposing body bias domain partitioning techniques and for body bias domain partitionings thereby generated, algorithms that search for body bias assignments. Several different granularities ranging from entire cores to small groups of standard cells were examined using two principal approaches: Designer aided pre-partitioning based determination of body bias domains and a first-time, fully automatized, netlist based approach called domain candidate exploration. Both approaches operate along the lines of activation and timing of standard cell groups. These approaches were evaluated using the example of a Dynamically Reconfigurable Processor (DRP), a highly efficient category of reconfigurable architectures which consists of an array of processing elements and thus offers many opportunities for generalization towards many-core architectures. Finally, the proposed methods were validated by manufacturing a test-chip. Extensive simulation runs as well as the test-chip evaluation showed the validity of the proposed methods and indicated substantial improvements in energy efficiency compared to the state of the art. These improvements were accomplished by the fine-grained partitioning of the DRP design. This method allowed reducing dynamic power through supply voltage levels yielding higher clock frequencies using forward body biasing, while simultaneously reducing static power consumption in unused parts.Die Einführung von FDSOI Prozessen in gegenwärtigen Prozessgrößen ermöglichte die Nutzung von Substratvorspannung in nie zuvor dagewesenem Umfang. Substratvorspannung beeinflusst unter anderem eine zentrale Eigenschaft von Transistoren, die Schwellspannung. Mittels Substratvorspannung kann diese um mehr als 100mV erhöht oder gesenkt werden, was es ermöglicht, die schiere Physik des Schaltvorgangs zu manipulieren. Da weiterhin hiervon der Signalpegel der digitalen Signale unberührt bleibt, kann diese Technik auch in feineren Granularitäten angewendet werden, als z.B. Dynamische Spannungs- und Frequenz Anpassung (Engl. Dynamic Voltage and Frequency Scaling, Abk. DVFS). Da jedoch der Stand der Technik Substratvorspannung hauptsächlich in Kombinationen mit DVFS anwendet, werden feinere Granularitäten, welche für DVFS nicht mehr wirtschaftlich realisierbar sind, nicht berücksichtigt. Die vorliegende Arbeit schließt diese Lücke, indem sie Partitionierungsalgorithmen zur Unterteilung eines Entwurfs in Substratvorspannungsdomänen vorschlägt und für diese hierdurch unterteilten Domänen entsprechende Substratvorspannungen berechnet. Hierzu wurden verschiedene Granularitäten berücksichtigt, von ganzen Prozessorkernen bis hin zu kleinen Gruppen von Standardzellen. Diese Entwürfe wurden dann mit zwei verschiedenen Herangehensweisen unterteilt: Chipdesigner unterstützte, vorpartitionierungsbasierte Bestimmung von Substratvorspannungsdomänen, sowie ein erstmals vollautomatisierter, Netzlisten basierter Ansatz, in dieser Arbeit Domänen Kandidaten Exploration genannt. Beide Ansätze funktionieren nach dem Prinzip der Aktivierung, d.h. zu welchem Zeitpunkt welcher Teil des Entwurfs aktiv ist, sowie der Signallaufzeit durch die entsprechenden Entwurfsteile. Diese Ansätze wurden anhand des Beispiels Dynamisch Rekonfigurierbarer Prozessoren (DRP) evaluiert. DRPs stellen eine Klasse hocheffizienter rekonfigurierbarer Architekturen dar, welche hauptsächlich aus einem Feld von Rechenelementen besteht und dadurch auch zahlreiche Möglichkeiten zur Verallgemeinerung hinsichtlich Many-Core Architekturen zulässt. Schließlich wurden die vorgeschlagenen Methoden in einem Testchip validiert. Alle ermittelten Ergebnisse zeigen im Vergleich zum Stand der Technik drastische Verbesserungen der Energieeffizienz, welche durch die feingranulare Unterteilung in Substratvorspannungsdomänen erzielt wurde. Hierdurch konnten durch die Anwendung von Substratvorspannung höhere Taktfrequenzen bei gleicher Versorgungsspannung erzielt werden, während zeitgleich in zeitlich unkritischen oder ungenutzten Entwurfsteilen die statische Leistungsaufnahme minimiert wurde

The optimal control of power electronic embedded networks in More Electric Aircraft

With the advancement of power electronic technologies over recent decades, there has been an overall increase in the utilisation of distributed generation and power electronic embedded networks in a large sphere of applications. Probably one of the most prominent areas of utilisation of new power electronics embedded systems is the use in power networks onboard military and civilian aircraft. With environmental concerns and increased competition in the civil aviation sector, more aircraft manufactures are replacing and interfacing electrical alternatives over heavier, less efficient and costly pneumatic, hydraulic and mechanical systems. In these modern power systems, the increased proliferation of power electronic converters and distributed generation raises important issues in regards to the performance, stability and robustness between interfaced switching units. These phenomena, such as power electronic sub-system interactions, become even more prominent in micro-grid applications or other low voltage distribution systems where interfaced converters are in close proximity to one another. In More Electric Aircraft (MEA), these interfaced power electronic converters are connected to the same non-stiff low power AC grid, which further increases the interactive effects between converter sub-systems. If these effects are not properly taken into account, then external disturbances to the system at given operating conditions can result in degradation of the system performance, failure in meeting the operating requirements of the grid, or in the worst case, instability of the whole grid. With much research in the area of decreasing the size and weight of systems, there is much literature proposing optimisation methods which decrease the size of filters between interfacing converters. Whilst effectively decreasing the size of these systems, interactions between interfaced converters gets worse, and is often improperly accounted for. The work presented in this thesis proposes a novel approach to the decentralisation and optimisation of converter controls on a power electronics embedded power network. In order to account for the interactive dynamics between sub-systems in the environment of reduced passive filter networks, all the system dynamics including the interactive terms are modelled globally. An optimal controller design approach based on the H2 optimisation is proposed to synthesise and generate automatically the controller gains for each power electronic sub-system. H2 optimisation is a powerful tool, which not only allows the submission, optimisation and development of closed loop controls for large dynamic systems, but offers the ability to the user to construct the controller for given structures. This enables the development of decentralised controllers for every sub-system with intrinsic knowledge of the closed loop dynamics of every other interconnect sub-system. It is shown through simulation and by experimental validation that this novel approach to grid control optimisation not only can improve overall dynamic performance of all sub-systems over 15traditional methods of design, but can also intrinsically reduce or better yet mitigate against the interactive effects between all converters. In addition, this method of controller design will be shown to not only be scalable to expanding sizes of grids, but the Phase-locked loops (PLLs) integrated to grid connected devices can also be considered in the optimisation procedure. PLLs are widely known to further cause interactive behaviours between grid interfaced devices. Including this into the optimisation also has been validated experimentally to prevent interactions on the grid, and improve performance over traditional design methods. Adaptations to the controller are performed to ensure operation in variable frequency environments (as is common in MEA), as well as methods of single converter optimisation when interfacing to an unknown grid. Additionally some initial research towards an adaption of the H2 controller to incorporate robustness as well as performance into the optimisation procedure is presented with mathematical concepts shown through simulation

Investigation of Control Concepts for High-Speed Induction Machine Drives and Grid Side Pulse-Width Modulation Voltage Source Converters

Control of a low voltage ac/dc/ac converter for high-speed induction machine drive applications has been investigated. Such a configuration can be applied, for example, in microturbines and high-speed spindles. Scalar control is usually applied for the control of high-speed drives especially in the case of very high-speed drives. Indirect rotor-flux-oriented control and direct torque control are designed and compared for the control of an exemplary high-speed induction machine drive. The 2L VSC is the most widely applied converter for high-speed drives. However, the 3L-NPC VSC is an attractive topology if drastically increased switching frequencies are required. A detailed comparison between a 2L VSC and a 3L-NPC VSC as the machine side converter of the exemplary high-speed induction machine drive is carried out. Voltage-oriented control is applied for the control of the grid side PWM active front end converter. In several industrial applications PWM active front end converters commonly operate in parallel to thyristor converter fed dc drives. Behavior of the voltage-oriented controlled active front end converter with L-filter in the presence of a parallel thyristor converter is investigated. The design of the LCL-filter components according to the given maximum grid current harmonics (e.g. IEEE-519) is a complex task. So far a precise and clear design procedure has not been presented. A new procedure to design the grid side filter (L- and LCL-filter) is proposed using the analytical expression of the converter voltage harmonics based on Bessel functions to achieve the compliance with the grid standard of IEEE-519. Voltage-oriented control with active damping is used to control the active front end converter with LCL-filter. A simple method is proposed to design the required lead-lag compensator in the active damping loop

Characterization and Modelling of Composites, Volume II

Composites have been increasingly used in various structural components in the aerospace, marine, automotive, and wind energy sectors. Composites’ material characterization is a vital part of the product development and production process. Physical, mechanical, and chemical characterization helps developers to further their understanding of products and materials, thus ensuring quality control. Achieving an in-depth understanding and consequent improvement of the general performance of these materials, however, still requires complex material modeling and simulation tools, which are often multiscale and encompass multiphysics. This Special Issue is aimed at soliciting promising, recent developments in composite modeling, simulation, and characterization, in both design and manufacturing areas, including experimental as well as industrial-scale case studies. All submitted manuscripts will undergo a rigorous review and will only be considered for publication if they meet journal standards